Restoring Sight to the Blind

Researchers at my university, Technion, have developed a process that may help restore sight to many of those who are currently sightless.

Here is how it works: (described in Nature Communications): Stem cells are adapted, using gene transplants, to make them sensitive to light, and are then introduced into the retina of those whose retinas are damaged. Then holography is used to stimulate those cells, to transmit images to the brain. (See diagram).

Blindness is often caused by conditions like retinitis pigmentosa, an inherited disease in which degrading light-sensing cells in the retina cause blindness.One in 4,000 people in the United States are affected by retinitis pigmentosa, and research on restoring vision can potentially help tens of thousands of Americans see again. “The basic idea of optogenetics is to take a light-sensitive protein from another organism, typically from algae or bacteria, and insert it into a target cell, and that photosensitizes the cell,” explained Dr. Shy Shoham, who led the study. If retinal nerve cells are primed by gene therapy that uses these light-sensitive proteins, they can then be gradually activated by rapid bursts of light In a paper published in the Feb. 26 issue of Nature Communications, the researchers led by Dr. Shoham explain how light from computer-generated holography can be used to stimulate genetically repaired cells in mouse retinas. They say that the key is to use a light stimulus that is intense, precise, and can trigger activity across a variety of cells at the same time. “Holography, what we’re using, has the advantage of being relatively precise and intense,” Shoham said. “And you need those two things to see.”

Arthur Clarke, the science fiction writer, once wrote that truly advanced technology is indistinguishable from magic. Bringing sight to millions of blind persons is truly magic. I can’t imagine a more worthy pursuit, or one that is more technically challenging. Kudos to Dr. Shoham and his ambitious team.